Wang Q, Zhou Y, Chen K, Ju X
Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China.
School of Medicine, Jiangsu University, Zhenjiang, China.
Insect Mol Biol. 2016 Aug;25(4):347-54. doi: 10.1111/imb.12224. Epub 2016 Mar 11.
Peroxiredoxins (Prxs) play an important role in the protection of insects against the toxicity of reactive oxygen species. Here, we identified and characterized a novel, atypical 2-cysteine (Cys) peroxiredoxin (BmPrx3) from an expressed sequence tag database in a lepidopteran insect, Bombyx mori. The BmPrx3 cDNA contained an open reading frame of 684 bp that encodes a 228-amino-acid protein with a calculated molecular mass of 25 kDa. Sequence comparison revealed that BmPrx3 belongs to the atypical 2-Cys Prxs. Quantitative real-time PCR revealed that BmPrx3 can be detected in all tissues and developmental stages. Recombinant BmPrx3 purified from Escherichia coli exhibited antioxidant activity that removed hydrogen peroxide and protected DNA from oxidative damage. Disc diffusion and viability assays revealed that recombinant BmPrx3 increased bacterial survival under H2 O2 -mediated oxidative stress. In addition, quantitative real-time PCR analysis indicated that BmPrx3 transcription levels were significantly increased in response to various oxidative stresses. Furthermore, BmPrx3 transcription levels in the midgut were regulated by bacterial infection. Taken together, these results suggest that BmPrx3 acts as an antioxidant enzyme to protect the silkworm from various oxidative stresses.
过氧化物酶（Prxs）在保护昆虫免受活性氧毒性方面发挥着重要作用。在此，我们从鳞翅目昆虫家蚕的一个表达序列标签数据库中鉴定并表征了一种新型的非典型2-半胱氨酸（Cys）过氧化物酶（BmPrx3）。BmPrx3 cDNA包含一个684 bp的开放阅读框，编码一个228个氨基酸的蛋白质，计算分子量为25 kDa。序列比较显示BmPrx3属于非典型2-Cys Prxs。定量实时PCR显示，在所有组织和发育阶段均可检测到BmPrx3。从大肠杆菌中纯化的重组BmPrx3表现出抗氧化活性，能够清除过氧化氢并保护DNA免受氧化损伤。纸片扩散法和生存力测定显示，重组BmPrx3在H2O2介导的氧化应激下提高了细菌的存活率。此外，定量实时PCR分析表明，BmPrx3的转录水平在各种氧化应激反应中显著增加。此外，中肠中的BmPrx3转录水平受细菌感染的调节。综上所述，这些结果表明BmPrx3作为一种抗氧化酶保护家蚕免受各种氧化应激。
